Python - if function is called

import functools
 
 
def calltracker(func):
    @functools.wraps(func)
    def wrapper(*args):
        wrapper.has_been_called = True
        return func(*args)
    wrapper.has_been_called = False
    return wrapper
 
@calltracker
def doubler(number):
    return number * 2
 
if __name__ == '__main__':
    if not doubler.has_been_called:
        print("You haven't called this function yet")
        doubler(2)
 
    if doubler.has_been_called:
        print('doubler has been called!')
        
# http://www.blog.pythonlibrary.org/2017/03/10/python-how-to-tell-if-a-function-has-been-called/